1. Department of Physics and Chemistry, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
2. Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
3. School of Physics, Korea Institute for Advanced Study, Seoul 02455, Republic of Korea
4. Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
5. Research Center for Functional Materials, National Institute for Materials Science, Tsukuba 305-0044, Japan
6. International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba 305-0044, Japan
7. Asia Pacific Center for Theoretical Physics, Pohang 37673, Republic of Korea
8. Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Republic of Korea